| Self-pollination | Cross pollination |
| If the pollen grains are transferred from the anther of a flower to stigma of the same flower, is known as SELF POLLINATION. | If the transfer of pollen grains takes place from the anther of one flower to the stigma of another flower, it is called CROSS POLLI – NATION. |
| It is possible only in bisexual flowers | It happens in both unisexual and bisexual flowers. |
| It may happen even without blooming of the flower | It happens only after blooming of the flower |
| Pollinating agents such as insects, air, water etc. may not necessary. | Pollinating agents such as insects, air; water etc. are necessary. |
